Whole Foods has received a warning letter from the Food and Drug Administration (FDA) on Wednesday over unsanitary conditions and possible risk of Listeria.

In the letter, the FDA specified its findings from the inspection conducted in February in the company's 70,000-square-foot food preparation facility in Everett, Massachusetts. The facility was said to be packing and preparing food under "insanitary conditions whereby they may have been contaminated with filth or rendered injurious to health."

According to authorities, various food items like pesto pasta, mushroom quesadillas, egg salad and couscous were found in areas where "condensate from ceiling joints was dripping onto the surface below."

In a news report published in Time, FDA laboratory analysis of swabs taken from the surfaces where food was placed confirmed the presence of the bacteria Listeria welshimeri. The bacteria found may be incapable of causing a disease, but its presence still indicates the probable presence of Listeria monocytogens.

Employees have also been seen handling exposed products without washing their hands or changing gloves after cleaning the work surfaces.

Other violations include dirty dishes near food, sinks without hot water for hand washing, and an employee who sprayed ammonium-based sanitizer on "an open colander of salad leafy greens."

According to the FDA, Whole Foods - a company that makes ready-to-eat foods available in 74 stores in Northeastern states - did not offer sufficient documentation about how it plans to address the problems in its facility and ensure compliance with health and safety standards, Boston Globe reported.

Ken Meyer, Whole Foods' global vice president for operations, said in a statement that he was "surprised" at the warning and that the company has taken "thorough and tangible steps" to address the problem.

"We've been in close contact with the FDA, opened our doors to inspectors regularly since February and worked with them to address every issue brought to our attention," Meyer said.

In October last year, Whole Foods dealt with another listeria scare, where the company had recalled blue cheese and various salad bar items.

Despite health concerns, Whole Foods has just recently opened its first 365 by Whole Foods Market store in California, which offers cheaper grocery products aimed at urban Millennials.